The human eye is an amazing feat of engineering, but its component parts can seem quite mysterious. If you can’t tell your retina from your cornea, this diagram explains how our eyes allow us to view the world...
1. Vitreous humour - A clear jelly-like substance that fills the back two-thirds of the eye and allows light to pass through without interference.
2. Conjunctiva - A moist protective membrane found on the inner eyelids and the outer eyeball that contains infection-fighting properties.
3. Iris - The coloured part of the eye, which contains the muscles that adjust the pupil size, controlling how much light reaches the back of the eye.
4. Pupil - Light is channelled through the iris’s central aperture, known as the pupil, and characterised by its black appearance.
5. Lens - Tucked behind the pupil, the lens focuses on close or distant images before directing light towards the retina.
6. Cornea - This clear part of the frontal eye protects the iris and pupil, and has a distinct semi-circular shape when viewed side-on.
7. Sclera - Visible as the white part of the eye, this is the eyeball’s supportive and protective outer wall.
8. Retina - Like the film in a camera, the back of the eye is a light-sensitive membrane designed to translate images into electronic signals. Colours are processed by cone-shaped photoreceptors, while their rod-shaped counterparts handle night vision and movement.
9. Optic nerve - The retina’s electronic signals are dispatched along the optic nerve to the brain’s visual cortices.
Our eyes struggle to view the same object for long periods, yet we spend hours every day staring at our phones and computer screens. To help prevent headaches and tiredness, take a moment every half-hour to look into the distance and give the eye muscles a chance to relax...
Choosing new glasses is a very important decision. As one of your face’s most instantly noticeable features, glasses are a significant style statement.
They should also provide you with crystal-clear vision that suits your lifestyle and daily activities. Small rectangular lenses can work well for people who need reading glasses, whereas larger wrap around lenses are practical for anyone who relies on their peripheral vision for work or leisure. Choosing frames is a personal decision that depends on everything from your age to your budget. However, we can offer expert guidance on which glasses look best and what designs would be most practical:
Facial features - Differently-shaped faces often benefit from particular styles of frames. For instance, high cheekbones and dainty features suit small curvy frames, whereas a round face can gain definition with angular frames. Eyes should be central within the lens openings, and the top frame should be just below your eyebrow line. Remember that new glasses should always complement your best features, rather than hiding them.
Prescription strength - Those wafer-thin frameless glasses can look great, but they’re designed for thin lenses that provide mild vision correction. Although slimmed-down lenses knock millimetres off normal thicknesses, we’d still recommend solid frames for anyone with a stronger prescription.
Comfort - If you’re going to be wearing glasses for most of the time, comfort is a top priority. Try different frames on, to see how they balance on the nose and rest against the ears. Do they sit symmetrically, and feel as though they’re securely held in place even when you look down at the floor? Remember that your new purchase can be adjusted in the practice to provide an optimal fit.
Typical uses - If you spend all day looking down at documents and back up to a computer screen, larger frames and lenses will prevent you looking over or under the frames – which can lead to headaches as your eyes constantly refocus. If all you need is reading glasses, then being able to see over the frames can actually be an advantage.
Bring a friend along! - They are able to see you from all angles and offer impartial opinions about which frames suit you the best; selfies can only do so much!
Contact lenses are very popular among people with active lifestyles or outdoor jobs, and today’s leading ranges can provide crystal-clear vision at varying distances. While early contact lenses were produced in the Victorian era from glass, most modern contact lenses are made with softer materials like silicone hydrogel that allow plenty of oxygen to reach the eye’s surface. These wafer-thin lenses should be treated with respect, but looking after them can be very straightforward.
Daily disposable contact lenses represent the ultimate in no-fuss vision correction, since they can be binned after a single use. They’re supplied in individual blister packs and inserted in seconds, though it’s essential to have clean hands and to apply make-up after rather than beforehand. Removing daily disposables becomes second nature, even for children.
Many people favour reusable lenses, which are stored overnight in small circular containers. These cases should be regularly sterilised and air-dried, and we can recommend which cleaning solutions can be used to care for the cases and the lenses.
A gentle rub between thumb and forefinger may help to remove any surface impurities from contact lenses, though some cleaning solutions will take care of this by themselves. It’s also advisable to keep a bottle of eye drops handy to counteract any dryness or irritation.
Regular eye examinations are vital to maintain clear vision and identify subtle changes in sight levels, but what actually happens during a routine eye test? These are the key stages:
Your history - To begin with, we’ll ask whether you are experiencing any specific health problems or potentially sight-related concerns, like headaches. Your overall health and current medications may be relevant, alongside details of previous sight problems or family histories of conditions.
Refraction - Those bulky spectacles and interchangeable lenses help us to determine what prescription strength will give you the clearest sight.
Muscle balance - By moving an object in front of your face, we can check your eye muscles are co-ordinated and ensure you have comfortable vision at varying distances.
Lifestyle - To assess your individual needs, we might ask about your occupation and sporting/leisure activities. This helps us compile a detailed understanding of your eye health and vision levels, plus any requirements you may have.
Pupil - reflexes Shining a light into your eyes allows us to check that your pupils react normally to light, since some neurological disorders may cause abnormal pupil reflexes.
Ophthalmoscopy - This health assessment is a critical stage of the test. Conditions including diabetes, cataracts and macular degeneration can be identified by your optometrist viewing your eyes through a series of lenses in a darkened room, while you look in different directions.
Intra-ocular pressures - If the fluid inside your eye has elevated pressure, it can indicate glaucoma. This is a disease that can seriously damage your sight if undetected. This test is usually performed on patients over 40 years of age, especially if there’s a family history of glaucoma.
Visual field testing - Loss of peripheral vision is one of the main signs of glaucoma, and visual field testing may also identify other neurological disorders.
At the end of the examination, we will explain our findings and give you a copy of your prescription or a statement explaining whether you need vision correction products. If you do, we can discuss the best options with you...